linux内核init进程函数的部分代码如下： 01 if (execute_command)
02 run_init_process(execute_command);
03
04 run_init_process("/sbin/init");
05 run_init_process("/etc/init");
06 run_init_process("/bin/init");
07 run_init_process("/bin/sh");
08
09 panic("No init found. Try passing init= option to kernel.");
10 }
代码中我们看出，linux内核在初始化的最末段，也就是挂载了跟文件系统之后，开始了与根文件系统，也就是用户应用的沟通，我们看到：内核分别尝试了/sbin/init, /etc/init, /bin/init, /bin/sh四个应用的执行，由此可以想到，只要我们准备相应的应用，并且只要满足其中之一，就可以启动系统了，如果任何的一个都没有满足，那么久会出现很经典的内核panic：No init found. Try passing init= option to kernel. 在此，我们利用现有分析，构建一个可以说是很小的根文件系统，busybox是针对嵌入式开发需求，集各种unix工具于一身的很小很强大的工具集。busybox的编译过程不再赘述，现假设busybox编译后已经生成� ......
1.A. extract the install file
tar zxvf bxviewer.tar.gz
cd bxviewer
./installbxv
logout
1.B. if system can't find bxv after ur installation, you can always set
it up by hand
if u use bash
vi ~/.bash_profile
add two lines at the end of the file:
export LD_LIBRARY_PATH=${installdir}
export PATH=$PATH:${installdir}
where ${installdir} is the dir where bxv and lib*.so located
sudo cp lib*.so /usr/lib ......
sudo apt-get build-dep firefox
若出现下面的错误：
不能满足软件包 firefox 所要求的构建依赖关系
请将 /etc/apt/sources.list 改为默认的源 有就是 装完系统后自带的：
#deb cdrom:[Ubuntu 9.04 _Jaunty Jackalope_ - Release i386 (20090421.3)]/ jaunty main restricted
# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
# newer versions of the distribution.
deb http://cn.archive.ubuntu.com/ubuntu/ jaunty main restricted
deb-src http://cn.archive.ubuntu.com/ubuntu/ jaunty main restricted
## Major bug fix updates produced after the final release of the
## distribution.
deb http://cn.archive.ubuntu.com/ubuntu/ jaunty-updates main restricted
deb-src http://cn.archive.ubuntu.com/ubuntu/ jaunty-updates main restricted
## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team. Also, please note that software in universe WILL NOT receive any
## review or updates from the Ubuntu security team.
deb http://cn.archive.ubuntu.com/ubun ......
1、系统时钟(System Clock)与实时时钟(Real Time Clock)
实时时钟指的是硬件时钟，而系统时钟指的是软件时钟，存在于Linux系统之中。当系统启动时，Linux会从硬件读取时间做为系统时间，之后便一直采用系统时间。Linux命令date可以用来设置系统时钟，而hwclock或者clock则用来设置实时时钟，即硬件时钟。
2、时钟频率
单位时间内晶体振荡器所产生的时钟脉冲个数，采用宏CLOCK_TICK_RATE表示。
3、时钟中断频率(HZ)
单位时间内产生的时钟中断次数，采用宏HZ表示。
4、时钟中断周期
采用tick表示，单位为毫秒。因此，时钟中断周期可由以下公式求得
tick = 1000000/HZ
为了在上式右边不能被整除时实现四舍五入，Linux将上述等式修正为
tick = (1000000+HZ/2)/2
5、LATCH
一个时种中断周期中所包含的时种周期。因此，LATCH可由以下公式求得
LATCH = (1/HZ)/(1/CLOCK_TICK_RATE) = CLOCK_TICK_RATE/HZ
为了在上式右边不能被整除时实现四舍五入，Linux将上述等式修正为
LATCH = (CLOCK_TICK_RATE+HZ/2)/HZ
6、jiffies
该全局变量表示系统自启动以来所经过的嘀答(tick)数，数据结构为32位无符号整数。改变量同常在内核中做为时间使用。
7、xtime
该全局变量� ......
#include <stdio.h>
#include <stdlib.h>
#include <dirent.h>
#include <errno.h>
#include <string.h>
#define MAX 1024
int get_file_count(char *root)
{
DIR *dir;
struct dirent * ptr;
int total = 0;
char path[MAX];
dir = opendir(root); /* 打开目录*/
if(dir == NULL)
{
perror("fail to open dir");
exit(1);
}
errno = 0;
while((ptr = readdir(dir)) != NULL)
{
//顺序读取每一个目录项；
//跳过“..”和“.”两个目录
if(strcmp(ptr->d_name,".") == 0 || strcmp(ptr->d_name,"..") == 0)
{
continue;
}
//printf("%s%s\n",root,ptr->d_name);
//如果是目录，则递归调用 get_file_count函数
if(ptr->d_type == DT_DIR)
{
sprintf(path,"%s%s/",root,ptr->d_name);
//pr ......
#include <stdio.h>
#include <stdlib.h>
#include <dirent.h>
#include <errno.h>
#include <string.h>
#define MAX 1024
int get_file_count(char *root)
{
DIR *dir;
struct dirent * ptr;
int total = 0;
char path[MAX];
dir = opendir(root); /* 打开目录*/
if(dir == NULL)
{
perror("fail to open dir");
exit(1);
}
errno = 0;
while((ptr = readdir(dir)) != NULL)
{
//顺序读取每一个目录项；
//跳过“..”和“.”两个目录
if(strcmp(ptr->d_name,".") == 0 || strcmp(ptr->d_name,"..") == 0)
{
continue;
}
//printf("%s%s\n",root,ptr->d_name);
//如果是目录，则递归调用 get_file_count函数
if(ptr->d_type == DT_DIR)
{
sprintf(path,"%s%s/",root,ptr->d_name);
//pr ......
Linux C + + Training
Syllabus
________________________________________
1, Linux Operating System
System Environment: Ubuntu GNU / Linux, RedHat Linux AS5,
FreeBSD
Course Requirements: proficient use of commonly used Linux
/ UNIX commands.
Time: 1 week.
________________________________________
2, Linux C + + development environment to build, develop
the use of tools
Related content: vi, GCC, GDB, Make, CVS, Subversion,
Eclipse CDT
Course requirements:
Skilled use of vi text
editor;
Skilled use of GCC tool chain for compiling, debugging,
build an executable file or shared library / static library;
Skilled preparation of Makefile;
Skilled configuration, using two kinds of CVS and
Subversion version control tool;
Skilled configuration, use the Eclipse CDT development
tools.
Time: 1 week
________________________________________
3, C + + language
C + + is a
multi-paradigm programming language, com ......
Linux C + + Training
Syllabus
________________________________________
1, Linux Operating System
System Environment: Ubuntu GNU / Linux, RedHat Linux AS5,
FreeBSD
Course Requirements: proficient use of commonly used Linux
/ UNIX commands.
Time: 1 week.
________________________________________
2, Linux C + + development environment to build, develop
the use of tools
Related content: vi, GCC, GDB, Make, CVS, Subversion,
Eclipse CDT
Course requirements:
Skilled use of vi text
editor;
Skilled use of GCC tool chain for compiling, debugging,
build an executable file or shared library / static library;
Skilled preparation of Makefile;
Skilled configuration, using two kinds of CVS and
Subversion version control tool;
Skilled configuration, use the Eclipse CDT development
tools.
Time: 1 week
________________________________________
3, C + + language
C + + is a
multi-paradigm programming language, com ......
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